!25 优化redis在scan查询时当前游标没有数据的场景

Merge pull request !25 from yechuankai/master

server/internal/redis/api/redis.go

@@ -206,8 +206,31 @@ func (r *Redis) Scan(rc *ctx.ReqCtx) {
 	mode := ri.Info.Mode
 	if mode == "" || ri.Info.Mode == entity.RedisModeStandalone || mode == entity.RedisModeSentinel {
 		redisAddr := ri.Cli.Options().Addr
-		keys, cursor := ri.Scan(form.Cursor[redisAddr], form.Match, form.Count)
+		//汇总所有的查询出来的键值
+		var keys []string
+		//有通配符或空时使用scan，非模糊匹配直接匹配key
+		if form.Match == "" || strings.ContainsAny(form.Match, "*") {
+			cursorRes[redisAddr] = form.Cursor[redisAddr]
+			for {
+				ks, cursor := ri.Scan(cursorRes[redisAddr], form.Match, form.Count)
 				cursorRes[redisAddr] = cursor
+				if len(ks) > 0 {
+					//返回了数据则追加总集合中
+					keys = append(keys, ks...)
+				}
+				//匹配的数量满足用户需求退出
+				if int32(len(keys)) >= int32(form.Count) {
+					break
+				}
+				//匹配到最后退出
+				if cursor == 0 {
+					break
+				}
+			}
+		} else {
+			//精确匹配
+			keys = append(keys, form.Match)
+		}
 
 		var keyInfoSplit []string
 		if len(keys) > 0 {
@@ -233,20 +256,40 @@ func (r *Redis) Scan(rc *ctx.ReqCtx) {
 		}
 	} else if mode == entity.RedisModeCluster {
 		var keys []string
-
+		//有通配符或空时使用scan，非模糊匹配直接匹配key
+		if form.Match == "" || strings.ContainsAny(form.Match, "*") {
 			mu := &sync.Mutex{}
 			// 遍历所有master节点，并执行scan命令，合并keys
 			ri.ClusterCli.ForEachMaster(ctx, func(ctx context.Context, client *redis.Client) error {
 				redisAddr := client.Options().Addr
-			ks, cursor, _ := client.Scan(ctx, form.Cursor[redisAddr], form.Match, form.Count).Result()
+				for {
+					cursorRes[redisAddr] = form.Cursor[redisAddr]
+					ks, cursor, _ := client.Scan(ctx, cursorRes[redisAddr], form.Match, form.Count).Result()
 					// 遍历节点的内部回调函数使用异步调用，如不加锁会导致集合并发错误
 					mu.Lock()
 					cursorRes[redisAddr] = cursor
+					if len(ks) > 0 {
+						//返回了数据则追加总集合中
 						keys = append(keys, ks...)
+					}
 					mu.Unlock()
+					//匹配的数量满足用户需求退出
+					if int32(len(keys)) >= int32(form.Count) {
+						break
+					}
+					//匹配到最后退出
+					if cursor == 0 {
+						break
+					}
+				}
 				return nil
 			})
 
+		} else {
+			//精确匹配
+			keys = append(keys, form.Match)
+		}
+
 		// 因为redis集群模式执行lua脚本key必须位于同一slot中，故单机获取的方式不适合
 		// 使用lua获取key的ttl以及类型，减少网络调用
 		keyInfoLua := `local ttl = redis.call('ttl', KEYS[1]);